Problems with the Microsoft Jet 4.0 OLE DB

[BlueVision]

I'am trying to work with databases (Microsoft Acces) and
everytime a recive this message error(I've created a string indicator and link it to the General Error Handler ) :
"Conn getDataToModify.vi"Object 0x2222222 is not valid."
I don't understand who is "Object 0x2222222 ".
Another message says that an error was encountered in the Microsoft Jet Engine.
Strange or not the program worked fine until this error.
How can I debug this ?

Thank you.

[DimensionFinder]

What are you using to communicate with Microsoft Access? Are you using Active X?

Can you create a small program that reproduces this error and post it here? That will help a lot.

Thanks

[AConaci]

Hey Blue Vision,

Did you find a solution to this problem? I'm dealing with the identical issue right now. Any clues would be appreciated.

Thanks

[AConaci]

In my case, the solution was as simple as replacing tunnels containing the Open DB reference on a For Loop with a shift register. Pretty obvious fix...what a relief!

[Antigraph]

* Chops wrote: In my case, the solution was as simple as replacing tunnels containing the Open DB reference on a For Loop with a shift register. Pretty obvious fix...what a relief!

What's obvious about this? I don't see the logic at all. What's different about a loop tunnel and a shift register that's wired to itself inside a loop?

I did make this change, and it took away the problem, but I'd very much like to understand what was wrong with using a loop tunnel. It seemed like the obvious (i.e. sufficient but as simple as possible) choice to me.

[GovBob]

This is the basic dataflow paradigm. If you have a shift register or tunnel you have a loop of some sort. When using a tunnel on the first iteration of the loop the reference ends at the tunnel. On the second iteration of the loop the reference is lost (so to speak) since no code outside the loop executes while the loop is operating. If you use a shift register the reference is fed back to the beginning of the loop on the second iteration and everything is fine. Don't forget  to use the highlight execution and single stepping debug tools.

Hope this helps.